94 GUIDEBOOK OF THE WESTERN UNITED STATES. 
Above Electric bowlders of dark basalt and the outcropping edge 
of a sheet of similar material on the far side of the river indicate that 
a stream of basaltic lava once flowed down the river valley at least 
as far as Emigrant. Since it solidified the river has cut most of it 
away, leaving the two or three remnants noted. 
At Gardiner the traveler has arrived at the northern entrance to 
ellowstone Park. Descriptions of the park and the 
Gardiner. principal routes through it are given in other Govern- 
Elevation 5,287 feet. ment and private publications. The railroad route 
Population $36" to Yellowstone, Mont., the western entrance to the 
St. Paul 1,062 miles. ' : . 
park, is described in Survey Bulletin 612 (Guidebook 
of the western United States, Part B). 
MAIN LINE WEST OF LIVINGSTON. 
As the train leaves Livingston for the continuation of the westward 
journey, an excellent view can be obtained on the south of the entrance 
to the valley of the upper Yellowstone, sometimes called the ‘gate 
of the mountains.’’ West of Livingston the railway crosses the 
northern point of the Gallatin Range at Bozeman Pass. This pass 
was discovered by Capt. Clark, who crossed the summit on his return 
journey July 15, 1806. He expressed surprise at the ease with which 
he passed from the Gallatin Valley on the west to that of the Yellow- 
stone on the east. Although this is a low summit and an easy one 
to cross with a wagon or on foot, it offered a considerable obstacle to 
the railway, as it involved a climb from Livingston of 996 feet in 12.2 
miles. Originally the railway followed the creek with an easy grade 
nearly to its head and then reached the summit by a very steep ascent, 
but a few years ago a new roadbed having a regular grade from 
Livingston to the summit at Muir was established. 
The mountain side on the left (south) presents many interesting 
features, especially to one not familiar with mountains. Early in 
the summer light-green grassy slopes interspersed with patches of 
brush or groves of aspen extend partway up the mountain to the forest 
of evergreen trees that thrives upon the upper slopes. At the lower 
margin of the forest the trees appear singly or in groups, but higher up 
they cover the entire surface with their dense foliage. Here and there 
are the marks of old burns in which the tree trunks stand out as 
whitened skeletons that later fall headlong in a hopeless tangle and 
then are concealed by the second growth of trees. Late in the sum- 
mer the lower slopes may be brown, but with the coming of the early 
frosts the woods are bright with color, the soft yellow of the aspens 
blending with the reds and browns of the scrub maple and the oak. 
The lower limit of the timber, which seems to be fairly definite, is not 
